SAFETY FIRST IN TREE PLANTING 



m;:, 



In most of these cases, the parasite was relatively harm- 

 less in its own country, but when it reached a new coun- 

 try and found susceptible new hosts it attacked them 

 with infinitely more vigor than it did its native hosts. 



Large scale importation of forest tree stock has been 

 a more recent development than that of fruit and orna- 



Courtcsy of Professor R. E. Smith. 



WHAT ONE BLIGHT DID 



This shows what the western pear growers had to do to save many of their orchards after they let the 

 eastern fire blight parasite into the western fruit-growing regions. 



conditions existing, however, its complete eradication is 

 becoming more and more doubtful. If this effort fails, 

 profitable forestation with any five-needled pine in any 

 part of the United States will probably in time become 

 impossible. Will attract general attention within 15 years. 

 4. The European hard-pine blister rust and the pitch- 

 pine bud moth, recently discovered in im- 

 ported material. It is hoped that the 

 rust has been entirely eradicated; the 

 eradication of the moth is very doubtful 

 as it is widely distributed already. 



The parasites we have already im- 

 ported are merely samples of what we are 

 likely to receive in the future, if we do 

 not enforce efficient preventive measures. 

 There are a number of known destruc- 

 tive pests which have not so far ap- 

 peared in this country. For example, the 

 oak mildew, which has greatly troubled 

 European foresters for the past few years 

 and appears to be a much more harmful 

 parasite than our American mildew. The 

 pine twister (Cccoma pinitorqua) is an- 

 other parasite even more to be dreaded 

 than the blister rust. We should see 

 that these and other known pests do not 

 appear in the future. But more danger- 

 ous than the known harmful parasites are 

 the hundreds of obscure foreign fungi, 

 doing little or no damage in their native 



mental plants. As a consequence, fewer forest 

 parasites have reached us. But we have already 

 had enough tree parasite invasions to give us 

 stern warning of the danger. The following 

 cases may be cited : 



1. Gypsy and browntail moths. From Europe. 

 Permanently established in New England and 

 slowly spreading. Millions of dollars have been 

 spent by the New England States, New York and 

 the Federal Government in attempted extermina- 

 tion. This is given up and nothing is now at- 

 tempted except the restriction of their migration 

 and holding them in check by natural parasites. 

 It took 20 years for the gypsy moth to attract 

 attention. 



2. Chestnut bark disease. Introduced from 

 the Orient, almost certainly on nursery stock. 

 Has already turned large areas of chestnut forest 

 into waste land, and is steadily spreading. Prob- 

 ably will exterminate the present stand of Ameri- 

 can chestnut, despite earnest but spasmodic con- 

 trol efforts. Took 15 years for this to attract 

 general attention. 



3. White pine blister rust. Present in numer- 

 ous importations from Europe. Thousands of dollars have 

 been spent, and hundreds of thousands of trees and cur- 

 rant and gooseberry bushes have been destroyed in the 

 effort to eradicate it. Scientifically this disease would 

 not be difficult to eradicate. With the social and political 



After C. L. Marlatt. 



WHITE PINES KILLED BY THE GYPSV MOTH 



Thousands of acres of forest have been wrecked by this introduced insect, and in 1907 Massa- 

 chusetts spent $750,000 in fighting the browntail and the gypsy moth in the effort to save 

 the trees of the State. 



habitats ; some even entirely unknown to science, as were 

 the chestnut bark fungus and citrus canker a few years 

 ago. Any of these, when introduced into this country 

 and given a chance at our great variety of forest trees, 

 is likely to find a very susceptible host species which it 



